Application of the restriction landmark genomic scanning (RLGS) method to rice cultivars as a new fingerprinting technique

The restriction landmark genomic scanning (RLGS) method was applied to rice, using two Japanese cultivars, Nipponbare and Koshihikari, and a Chinese landrace, LiuZhou'Bao'Ya'Zao'. More than 3000 landmarks were detected as spots on the individual autoradiograms of each cultivar. Nipponbare and LiuZhou' Bao'Ya'Zao' showed apparently different RLGS profiles, from which the genetic similarity (GS) between them was estimated as 0.344. Although the two Japanese cultivars, Nipponbare and Koshihikari showed quite similar RLGS profiles, they were easily distinguished on the basis of the presence or absence of specific spots; the GS value between them was calculated as 0.980. The RLGS method is shown to be a powerful fingerprinting technique, especially for the classification and identification of cultivars in rice and probably in other crops as well.     

Screening of turfgrass species and cultivars for NaCl tolerance

Summary Information regarding the relative levels of salt tolerance between cultivars of Kentucky bluegrass (Poa pratensis L.) is lacking. The objectives of this study were to 1) develop a simple, quick and sensitive method of screening turfgrass species for NaCl tolerance and 2) to compare the relative salt tolerance of five cultivars of Kentucky bluegrass (Ram I, Adelphi, Baron, Bensun, and Nassau) to other known salt tolerant turfgrass species such as alkalaigrass (Puccinellia distans (L.) Parl. cv. Fults) and two cultivars of red fescue (Festuca rubra L. Dawson, and Checker).Alkalaigrass and both cultivars of red fescue retained a high level of salt tolerance compared to the Kentucky bluegrass cultivars. Significant variability in salt tolerance was apparent among the Kentucky bluegrass cultivars with Adelphi and Ram I exhibiting the best overall tolerance.     

Genetic linkage maps of two apple cultivars (<Emphasis Type="Italic">Malus</Emphasis> × <Emphasis Type="Italic">domestica</Emphasis> Borkh.) based on AFLP and microsatellite markers

Genetic linkage maps for two apple cultivars were constructed using AFLP and SSR markers and the pseudo-testcross mapping strategy. The F₁-mapping population was produced by crossing the cultivar Braeburn to the cultivar Telamon and consisted of 257 individuals. Out of the 182 AFLP primer combinations screened, a total of 48 were selected. Using these, 463 AFLP markers segregating 1:1 in the progeny were identified, of which 231 were heterozygous in Telamon and 232 in Braeburn. Eighty-five AFLP markers present in both cultivars (3:1 segregation) were scored in the whole mapping population. Twenty-one SSR primer pairs were tested, which clearly screened 23 loci (some multi-locus markers). This resulted in the identification of 3 loci heterozygous only in Telamon (1:2:1), 5 loci heterozygous only in Braeburn (1:2:1) and 15 loci which were heterozygous in both cultivars (1:1:1:1). Two linkage maps were produced. The Telamon map comprised 259 markers (242 AFLPs and 17 SSRs) divided into 17 linkage groups. The total map length was 1039 cM with a marker density of 4.0 cM. At = 0.05, 8.9% of the mapped loci showed distorted segregation. The Braeburn map consisted of 264 markers (245 AFLPs and 19 SSRs) mapped on 17 linkage groups and spanning 1245 cM. The average distance between two markers was 4.7 cM and segregation distortion was observed for 18.6% of the mapped markers ( = 0.05). Fourty-six markers common to both maps (32 AFLPs and 14 SSRs) allowed the identification of 16 homologous linkage groups. The seventeenth pair of homologous linkage groups from Telamon and Braeburn was identified by 2 SSR markers which were in common to the genetic linkage maps of Fiesta and Discovery, two other apple cultivars.     

Water stress-induced oxidative damage and antioxidant responses in micropropagated banana plantlets

Oxidative injury and antioxidant responses were investigated in two banana genotypes (Musa AAA Berangan and Musa AA Mas) subjected to 40 % PEG-induced water stress. PEG treatment resulted in oxidative injury, as expressed in increased lipid peroxidation and reduced membrane stability index, in both cultivars; however, greater oxidative injury was detected in Mas. Under PEG treatment, catalase activity and glutathione reductase activity were enhanced in both cultivars, but were higher in Mas. Ascorbate peroxidase activity was enhanced in Berangan under water stress, but was unaffected in Mas. Meanwhile, superoxide dismutase activity was inhibited in both cultivars under water stress, but higher activity was detected in Berangan. Higher ascorbate peroxidase and superoxide dismutase activities were associated with greater protection against water stress-induced oxidative injury.     

Genetic analysis of brown planthopper resistance in twenty varieties of rice,Oryza saliva L.

Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu.     

Organogenesis from ‘Passe Crassane’ and ‘Old Home’ pear (Pyrus communis L.) protoplasts and isoenzymatic trueness-to-type of the regenerated plants

Summary Large numbers of highly viable mesophyll protoplasts were isolated from shoot cultures of the scion cv Passe Crassane and the rootstock genotype Old Home of common pear (Pyrus communis L.). Protoplasts were cultured for both genotypes either as liquid layers or as liquid-over-agar cultures, in ammonium-free MS medium with 0.5 M mannitol, 50 mg/l casein enzymatic hydrolysate (CEH), 2.0 mg/l NAA and 1.0 mg/l BAP, plus either 0.5 mg/l IAA (for Old Home) or 2.0 mg/l IAA (for Passe Crassane). Protoplast microcalli, obtained by day 60 (Passe Crassane) or day 80 (Old Home), were transferred for further growth to ammonium-free MS medium with 2.0 mg/l NAA and 1.0 mg/l BAP. Shoot bud regeneration from the protoplastderived callus was first attempted between 100 (Passe Crassane) and 120 (Old Home) days after protoplast isolation. For Passe Crassane, shoot buds were regenerated (day 130) on a half-strength MS medium with 0.1 mg/l IBA, 0.5 mg/l BAP, 50 mg/l CEH and 20 mg/l Ca-panthotenate. For Old Home, shoot but regeneration only occurred 30 days later and on the same medium as above, which was additionally supplemented with double the concentration of the group B vitamins found in the original MS formulation and 0.05 mg/l GA₃. Following micropropagation and in vitro rooting of shoots, the plants were transferred to soil following standard procedures. Trueness-to-type of the regenerated plants was assessed by analysing their leaf isozyme banding profiles (for EST, AP, PRX, SOD, ENP, LAP, PGI, AAT, ADH, MDH and PGM) and comparing them to those corresponding to the original shoots that provided the protoplasts. No differences between the mother shoots and the protoclones were observed for any one of the 11 isozyme systems studied.     

Heritable variation in the phaseolin protein of nondomesticated common bean,Phaseolus vulgaris L.

Summary Crude protein extracts from single seeds of nondomesticated Mexican bean accessions were analysed by SDS polyacrylamide gel electrophoresis for variability in phaseolin protein. Six new phaseolin types; M1, M2, M3, M4, M5, M6, which contained polypeptides within the same range of molecular weights (51,000 to 45,000 daltons) as occur in the S, T and C phaseolin types of cultivated beans were identified. No T and C types were found among the non-domesticated Mexican accessions, and the S type occurred in less than 7% of the seeds screened. Genetic analyses of F₂ progenies from crosses between Sanilac (S), and five of the M types showed that each M phaseolin phenotype was allelic to the S type and expressed codominantly.     

Genetic diversity in relation to heterosis and combining ability in spring wheat

Summary Genetic diversity among ten varieties of spring wheat used as parents in a diallel cross was assessed through multivariate analysis (D²-statistics) and then related to heterosis and SCA effects of their hybrids. The parents fell into three groups. Group I contained the varieties, Nobre, Girua and Carazinho; group II contained Sonalika, Lyallpur and Pitic 62 and group III contained Indus 66, Balaka, Sonora 64rs and MSl. The varieties of group I were good general combiners, while the varieties of group III were poor combiners. Significant heterotic and SCA effects for yield and yield components were observed in the hybrids of the parents belonging to different groups but not in the same group. Genetic divergence between the parents had a positive relationship with heterosis and SCA effects of the hybrids.     

Spontaneous chlorophyll mutants of Pennisetum americanum: Genetics and chlorophyll quantities

Summary Thirteen spontaneously occurring chlorophyll deficient phenotypes have been described and their genetic basis was established. Ten of these — white, white tipped green, patchy white, white virescent, white striping 1, white striping 2, white striping 4, fine striping, chlorina and yellow virescent showed monogenic recessive inheritance and the remaining three — yellow striping, yellow green and light green seedling phenotypes showed digenic recessive inheritance. The genes for (i) white tipped green (wr) and yellow virescent (yv) and (ii) patchy white (pw) and white striping 1 (wst 1) showed independent assortment. Further, the genes for white (w), white tipped green (wr) and yellow virescent (yv) were inherited independently of the gene for hairy leaf margin (Hm).In the mutants — white tipped green, patchy white, white striping 1, white striping 2, fine striping, chlorina, yellow virescent, yellow striping, yellow green and light green phenotypes total quantity of chlorophyll was significantly less than that in the corresponding controls, while in white virescent there was no reduction in the mature stage. For nine of the mutants the quantity of chlorophyll was also estimated in F₁'s (mutant x control green). In F₁'s of six of the mutants — white tip, patchy white, chlorina, yellow virescent, fine striping and yellow striping the quantity of chlorophyll was almost equal to the wild type. In the F₁'s of three of the mutants — white striping 1, white striping 2 and light green an intermediate value between the mutant and wild types was observed. In yellow virescent retarded synthesis of chlorophyll, particularly chlorophyll a was observed in the juvenile stage. Reduced quantity of chlorophyll was associated with defective chloroplasts. In the mutants — white tipped green, white virescent, fine striping, chlorina, yellow striping, yellow green and light green defective plastids were also observed. In patchy white secondary destruction of chlorophylls and the presence of defective plastids were found to be associated with reduced chlorophyll quantity at maturity.Paper chromatographic studies of leaf flavonoids revealed some variation between the inbreds, but there were three common spots, 7, 8 and 9, except for PDP in which the spot 8 was absent. Chlorophyll deficient mutants differed from their respective controls in the absence of one or more of the spots present in the controls and in the presence of new spots in some of the mutants.Most of the chlorophyll mutants showed higher survival rate in the Kharif season than in Rabi season which was attributed to the higher mean day temperature and longer day light period in the Kharif season than in Rabi season.     

Growth vigour of some Egyptian cotton variety seedlings in relation to selected rhizospheric microflora antagonistic toRhizoctonia solani Kuhn

Summary Growth responses of Ashmouni and Karnak cotton variety seedlings toRhizoctonia solani, the damping-off fungus, or toBacillus subtilis (two different strains),Aspergillus terreus andAspergillus flavus isolated from the rhizosphere of cotton, and all antagonistic to the pathogen, were expressed in terms of growth-vigour criteria.The presence ofR. solani in the soil inhibited the growth vigour of both cotton variety seedlings. However, Karnak seedlings were more sensitive to the pathogen than Ashmouni seedlings. One of the strains ofB. subtilis andA. terreus generally increased the vigour of both cotton variety seedlings.A. flavus lowered most of the growth criteria of Karnak or Ashmouni cotton seedlings.

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Zusammenfassung Rhizoctonia solani, der Parasiet von Baumwolle-Keimlingen, wurde isoliert.Sowohl Bacillus subtilis als auchAspergillus terreus und Aspergillus flavus wurden von der Rhizosphere der Baumwolle-Pflanzen isoliert. Diese Organismen wurden als antagonistisch gegenRhizoctonia solani erkannt. Die Wirkung dieser Organismen auf das Wachstum von Keimlingen der Baumwolle sorten Ashmouni und Karnak wurde untersucht. R. solani hemmt das Wachstum der Keimlinge beider Baumwolle-Sorten. Es wurde festgestellt, dass Karnak empfindlicher ist als Ashmouni. Einer der Stämme vonB. subtilis undA. terreus erwiesen sich als Wachstum förderend bei beiden Baumwolle-Sorten.A. flavus dagegen vermindert das Wachstum von Karnak und Ashmouni.

     

Green manures of oat,rape and sweet corn for reducing common root rot in pea (Pisum sativum) caused by Aphanomyces euteiches

Green manure crops of sweet corn, soybean, alfalfa, snap bean, rape, pea and of the two oat cultivars Dane and Troy were incorporated into the same soil and containers in which the crop had grown for five weeks. The soil was then evaluated for suppression of common root rot (Aphanomyces euteiches) of pea grown in infested pasteurized and non-pasteurized soils in the greenhouse. Pea biomass reduction and a plant bioassay for A. euteiches were used to measure the green manure suppression of disease. Green manures of sweet corn cv.Jubilee, oat cv.Troy, and rape cv.Humus significantly reduced pea biomass losses over the non-amended control soil treatments. Oat cv.Troyand sweet corn cv.Jubilee green manures significantly reduced inoculum density of A. euteiches over the corresponding fallow controls in inoculated pasteurized soil by 87% and 76%, respectively, and in inoculated non-pasteurized soil by 67% and 66%, respectively. Only the green manure of oat cv. Troy reduced inoculum density significantly below fallow.     

Endogenous abscisic acid and 2-trans-abscisic acid in alternate bearing ‘Wilking’ mandarin trees

The relationship of abscisic acid (ABA) and 2-trans-abscisic acid (t-ABA) to alternate bearing has been examined in Wilking mandarin (Citrus reticulata Blanco) trees. Leaves, stems and buds of trees loaded with fruit (on trees) had 4.3, 6.0 and 2.2 fold higher ABA levels than the corresponding organs from off trees. Leaves had higher ABA levels than stems and buds in both on and off trees. t-ABA was non-detectable in Wilking leaf, stem and bud tissue. Amounts of t-ABA not exceeding 40% of the ABA content, were found in Shamouti and Valencia orange buds and in Wilking fruit peel.The elevated levels of ABA in on tree organs may reflect a stress imposed by the fruit overload.     

Do nine-primaried passerines have nine or ten primary feathers? The evolution of a concept

The number of primary feathers in a birds wing has been used as a systematic character since the first half of the nineteenth century. During the years, though, the definition of which feathers to count as a primary has changed and today the species historically denoted as having only nine primaries are instead said to have, for example, nine functional primaries. In this study, I investigated the borderline between nine-primaried and ten-primaried birds to search for a proper definition of the term nine-primaried. A total of 161 specimens of 104 bird species, mainly passerines, were examined. All species examined had ten primaries although the nine-primaried species had primary ten more or less concealed under primary covert nine. The number of primary coverts has decreased over time, with ten primary coverts as the ancestral state within Passeriformes and nine primary coverts among most oscine species. In conclusion, a proper definition of nine-primaried might be with primary ten concealed by primary covert nine. This definition includes all taxa historically denoted nine-primaried, i.e. systematically it is a definition of a paraphyletic group. The term nine-primaried is thus too inclusive to be of more than very limited systemtic value and, consequently, the New World nine-primaried oscines group might gain from a new denotation.Electronic Supplementary Material Supplementary material is available for this article at     

Evaluation of an exotic maize population adapted to a locality

Summary An exotic Zea mays L. population (Tuxpeno) was adapted to North Carolina conditions by first introducing genes for adaptability from two North Carolina varieties ([(Jarvis X Indian Chief)Tuxpeno]Tuxpeno) including four generations of intermating, and then selecting for adaptability using maturity as the primary measure. The study evaluated selection for adaptability and the diversity available between adapted Tuxpeno and the local varieties, Jarvis and Indian Chief. Analytical procedures were developed to quantify the diversity between populations and the complementation of local varieties by introduced germ plasms. The analyses utilized the specific effects available from the diallel mating design.Three replicate selections responded similarly under simple recurrent mass selection (1/10) for the earliest disease-free plants initially and additionally for plant types (primarily height) in the final generation. The 1/4 local germ plasm permitted rapid adaptation of Tuxpeno gene pool to local conditions. The adapted Tuxpeno populations yielded similarly to the local populations with an average heterosis for grain yield of 28% when crossed to the local populations used as source of genes for adaptability. The diversity found between adapted Tuxpeno lines and these local varieties based on genes affecting grain yield was 1.5 to 2.5 times that measured between the local varieties (Jarvis and Indian Chief). Diversity lost through intergradation with local material was a reasonable investment. Yield genes introduced from Tuxpeno complemented local gene pools through nonadditive, primarily dominance-associated, gene effects. Reassortment of major gene blocks apparently occurred leading to significant divergence among replicate selections involving both additive-associated and dominance-associated gene effects.Paper No. 6355 of the North Carolina Agri. Res. Ser., Raleigh, NC. Research supported in collaboration with the Rockefeller Foundation and CIMMYT, D.F. (Mexico)     

Influence of the nitrogen level on root growth and morphology of two potato varieties differing in nitrogen acquisition

Two potato (Solanum tuberosum L.) cultivars (Astrid and Bodenkraft) differing in their nitrogen acquisition from the soil (Hunnius, 1981) were used in nutrient solutions to study the effect of increasing concentrations of nitrate (0.05; 0.5; 5.0 mol m^-3) particularly on root growth and morphology. In each variety increasing nitrogen concentrations stimulated shoot growth more than root growth. At all nitrate concentrations, the variety with higher nitrogen acquisition (Astrid) had a significantly larger root system. The larger root system of Astrid compared to Bodenkraft was particularly evident when surface area and total length of the roots, instead of root dry weight were used as parameters. The results stress the importance of root length and surface area for nitrogen acquisition from soils.     

A linkage map with RFLP and isozyme markers for almond

Inheritance and linkage studies were conducted with seven isozyme genes and 120 RFLPs in the F₁ progeny of a cross between almond cultivars Ferragnes and Tuono. RFLPs were detected using 57 genomic and 43 cDNA almond clones. Eight of the cDNA probes corresponded to known genes (extensin, prunin (2), -tubulin, endopolygalacturonase, oleosin, actin depolymerizing factor and phosphoglyceromutase). Single-copy clones were found more frequently in the cDNA (65%) than in the genomic libraries (26%). Two maps were elaborated, one with the 93 loci heterozygous in Ferragnes and another with the 69 loci heterozygous in Tuono. Thirty-five loci were heterozygous in both parents and were used as bridges between both maps. Most of the segregations (91%) were of the 11 or 1111 types, and data were analyzed as if they derived from two backcross populations. Eight linkage groups covering 393 cM in Ferragnes and 394 in Tuono were found for each map. None of the loci examined in either map was found to be unlinked. Distorted segregation ratios were mainly concentrated in two linkage groups of the Ferragnes map.     

Nucellar callus of ‘Femminello’ lemon,selected for tolerance toPhoma tracheiphila toxin,shows enhanced release of chitinase and glucanase into the culture medium

Phoma tracheiphila is the causative agent of the disease mal secco. Citrus cultivars differ substantially in respect to their sensitivity to the pathogenP. tracheiphila and its toxin. Some cultivars (e.g., Femminello lemon) are inherently sensitive while others (e.g., Tarocco orange) are tolerant. Cell lines derived from nucellar tissue of Femminello, Tarocco and a cell line selected for tolerance to the fungal toxin (Femminello-S) were used to study host-pathogen interaction. Our results showed that calli or conditioned media of Tarocco and Femminello-S inhibited the size of co-cultivated fungal colonies when compared to Femminello. In addition, conditioned medium of Tarocco as well as FemminelloS, but not Femminello, promoted bursting of hyphal tips. A ten-fold increase in chitinase and glucanase enzymatic activity, as evaluated by radiometric assay and laminarin hydrolysis respectively, was detected in Femminello-S extracellular extracts as compared to Femminello. An increase in chitinase was also shown by immunoblot analysis. Our findings suggest a positive correlation between the presence of chitinase and glucanase in the conditioned media of the cultured cells and the tolerance of those cells toP. tracheiphila toxin.     

Genetic analysis of resistance to whitebacked planthopper in twenty-one varieties of rice,Oryza sativa L.

Summary The inheritance of resistance to whitebacked planthopper Sogatella furcifera (Horvath) was studied in 21 rice varieties. Reactions of F₁; F₂ and F₃ progenies of the crosses of 21 resistant varieties with the susceptible variety TN 1 revealed that a single dominant gene governs resistance in Mushkan 41, Santhi, Siahnakidar 195, SM2-34, Tirisurkh 251, Zirijowaian 245, 18, 24A, 39, 76 S, 78, 180, 213 B, 267, 293, CI 6037-4, NP97, S39 JKW and Bansphul. In varieties 65 and 274 A, resistance is governed by one dominant and one recessive gene which segregate independently of each other. Tests for allelism with the Wbph 1 gene originally identified in N 22 revealed that the dominant gene present in all the test varieties is the same as Wbph 1. Further studies are required to determine the allelic relationships of the recessive gene found in varieties 65 and 274 A.     

Esterase isozymes in rye — characterization,genetic control and chromosomal location

Summary The zymogram phenotypes that Chinese Spring-Imperial, Holdfast-King II and Kharkov-Dakold wheat-rye addition lines presented for esterase isozymes were determined using polyacrylamide gel ectrophoresis. The analyses were carried out with different parts of the dry kernel, namely embryo plus scutellum and endosperm, leaves and roots. In all cases, embryo plus scutellum, endosperm and leaf presented different patterns of esterases. The patterns of leaves and roots were the same. Results indicate that rye esterases exist as monomers and dimers. Dimeric esterases are controlled by one locus located on the 3R chromosomes of Imperial, King II and Dakold rye cultivars. Five loci involved in the production of monomeric esterases have been located on the 6R chromosomes of these cultivars, specifically on the long arm of the King II 6R chromosome. On the basis of these results, considerations concerning chromosome homoeology and homology are made.     

Ionic relations of aeroponically-grown olive genotypes,during salt stress

Two olive (Olea europaea L.) genotypes, Frantoio and Leccino, were exposed to increasing concentrations of NaCl (0-30-60-120 mM) in an aeroponic cultivation system for 60 days. Dry weights and sodium and potassium contents of apical and basal leaves, new and old wood, and roots were measured to determine Na uptake rate, Na translocation rate and K-Na selectivity ratio (S_K,Na). Frantoio showed a higher salt resistance than Leccino. Frantoio and Leccino had a similar Na uptake rate, but largely differed for Na translocation to the shoot. Furthermore Frantoio exhibited a higher K-Na selectivity than Leccino at both whole plant level and above all at the level of shoot system. Resistance mechanism of Frantoio is probably related to Na esclusion by roots and to the ability to maintain an appropriate K/Na ratio in actively growing tissues.Research supported by National Research Council of Italy, Special project RAISA.